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THE EFFECT OF LEPIDOLITE IN A HIGH TENSION ELECTRICAL PORCELAIN BODY 1
Author(s) -
Twells Robert
Publication year - 1928
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1928.tb16512.x
Subject(s) - materials science , mica , vitrification , feldspar , mineralogy , composite material , chemistry , quartz , medicine , andrology
Lepidolite is a lithium mica which has had considerable commercial application in glass and enamels. Its use in porcelain has not been tried to any great extent. This work covers the replacement by lepidolite of the feldspar in a high tension electrical porcelain. The results show that changing the RO of the standard body by molecularly replacing K 2 O by Li 2 O raises the vitrification temperature of the body, but that replacing feldspar directly pound for pound by lepidolite greatly lowers the vitrification temperature of the body. Lepidolite gives porcelains having a fine appearance and extreme whiteness. The most important property noted is an improvement of the bodies containing lepidolite in resistance to thermal shocks. Owing to its higher cost it is unlikely that lepidolite will be used in porcelains except in small proportions with feldspar to produce bodies having special properties. As hitherto the most important applications of lepidolite will doubtless be in glasses and enamels where full benefit can be secured from its fluorine content and low fusion temperature.